Endogenous inhibitors of nitric oxide synthesis: how important are they?

In animals and humans, inhibition of nitric oxide (NO) production has widespread effects. Reduced activity of the NO:cyclic GMP pathway has been documented in disease states, including hypertension, diabetes and certain types of renal disease. Inhibitors of NO synthesis occur endogenously, and have been implicated in the regulation of the NO pathway in health and disease. Here we review the possible biological roles of endogenous NO synthase inhibitors, with particular reference to renal disease.